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arXiv math/0601007math.PR
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随机heat equation方程解的变分

Variations of the solution to a stochastic heat equation

Jason Swanson

摘要:

我们考虑一个随机热方程的解。该解是时间和空间的随机函数。对于空间中的不动点,所得到的时间随机函数$F(t)$具有非平凡的四次变分。因此,这个过程具有无限二次变差,并且不是半鞅。因此,经典的伊藤演算不适用。启发式的想法,一个可能的新的演算,这个过程的动机,我们导致研究修改的二次变分。也就是说,我们修改增量平方和中的每一项,使其均值为零。然后,我们表明,这些总和,作为$t$的功能,弱收敛到布朗运动。

英文摘要:

We consider the solution to a stochastic heat equation. This solution is a random function of time and space. For a fixed point in space, the resulting random function of time, $F(t)$, has a nontrivial quartic variation. This process, therefore, has infinite quadratic variation and is not a semimartingale. It follows that the classical Itô calculus does not apply. Motivated by heuristic ideas about a possible new calculus for this process, we are led to study modifications of the quadratic variation. Namely, we modify each term in the sum of the squares of the increments so that it has mean zero. We then show that these sums, as functions of $t$, converge weakly to Brownian motion.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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